As an example of a swing working machine, there is a hydraulic excavator. In general, the hydraulic excavator is formed of an undercarriage including traveling mechanism and a revolving upperstructure installed on the undercarriage, the undercarriage and the revolving upperstructure are connected to each other by a swing device, and the revolving upperstructure is configured to swing with respect to the undercarriage by the swing device. In the revolving upperstructure, front working mechanism is arranged. The front working mechanism is formed of a boom, an arm, and a front attachment.
As a working machine, there is a hydraulic excavator executing excavation work of soil for example. In the hydraulic excavator, a bucket is furnished as a front attachment, and excavation of the soil and the like is executed by the bucket. A hydraulic excavator provided with a surroundings monitoring device for monitoring the surroundings thereof during operation has been widely known from the past. As a concrete configuration of the surroundings monitoring device, such configuration is popular that a camera is furnished in a vehicle body and a display is arranged in a cab at a position forward of an operator seat on which an operator sits. An image photographed by the camera is made an image of a moving image state, and is displayed on a display screen.
In PATENT LITERATURE 1, there is disclosed one with a configuration of furnishing a plurality of cameras in a vehicle body in order to secure a wide visual field range in the surroundings of a working machine, and with a configuration of converting the viewpoint by signal processing of the monitoring image of the surroundings photographed by each camera in order to eliminate the dead angle of the monitoring view field over generally all periphery of the working machine on the display, and displaying the monitoring image on the display screen as a bird's eye view that is a plan view image projected on a plane. According to PATENT LITERATURE 1, cameras are installed at three positions of a rear position and right and left side part positions in the revolving upperstructure of the hydraulic excavator. Further, although the front of the hydraulic excavator is not imaged in PATENT LITERATURE 1 since the operator can have direct visual contact with the front, one installing a camera also in the front position is also known.
The optical axis of the photographing lens of each camera described above is directed obliquely downward. The images photographed by each of these cameras are through images, and an image as viewed from a top of the vehicle obtained by subjecting the through image to viewpoint conversion to an upper viewpoint is the bird's eye view.
Although the bird's eye view is displayed on the display screen, it is configured that an illustration obtained by symbolizing the working machine (a plan image showing the hydraulic excavator) is displayed on the display screen then as a vehicle icon, and that the bird's eye views obtained by respective cameras are disposed around the vehicle icon. According to PATENT LITERATURE 1, the vehicle icon is displayed at the center position of the display screen, respective upper viewpoint images are arrayed in a rear region and right and left side regions of the vehicle icon, and a composite bird's eye view as one for monitoring the surroundings is displayed.